<template>
  <div class="yearPicker" ref="yearPicker" :width="width">
    <i class="dateIcon el-icon-date"></i>
    <input
      class="_inner"
      ref="inputLeft"
      v-model="startShowYear"
      @focus="onFocus"
      @blur="onBlur"
      type="text"
      name="yearInput"
      @keyup="checkStartInput($event)"
      placeholder="开始年份"
    />
    <span>{{ sp }}</span>
    <input
      class="_inner"
      ref="inputRight"
      v-model="endShowYear"
      @focus="onFocus"
      @blur="onBlur"
      type="text"
      name="yearInput"
      @keyup="checkEndInput($event)"
      placeholder="结束年份"
    />
    <i class="delIcon el-icon-circle-close" v-show="showDel" @click="delTime"></i>
    <span class="_inner labelText" v-if="labelText != ''">{{ labelText }}</span>
    <div class="_inner floatPanel" v-if="showPanel">
      <div class="_inner leftPanel">
        <div class="_inner panelHead">
          <i class="_inner el-icon-d-arrow-left" @click="onClickLeft" style="top:17px"></i><span>{{ leftYearList[0] + "-" + leftYearList[9] }}</span>
        </div>
        <div class="_inner panelContent">
          <div
            :class="{
              oneSelected: item === startYear && oneSelected,
              startSelected: item === startYear,
              endSelected: item === endYear,
              betweenSelected: item > startYear && item < endYear,
            }"
            v-for="item in leftYearList"
            :key="item"
          >
            <a
              :class="{
                cell: true,
                _inner: true,
                selected: item === startYear || item === endYear,
              }"
              @click="onClickItem(item)"
            >
              {{ item }}
            </a>
          </div>
        </div>
      </div>
      <div class="_inner rightPanel">
        <div class="_inner panelHead">
          <i class="_inner el-icon-d-arrow-right" @click="onClickRight" style="top:17px"></i><span >{{ rightYearList[0] + "-" + rightYearList[9] }}</span>
        </div>
        <div class="_inner panelContent">
          <div
            :class="{
              startSelected: item === startYear,
              endSelected: item === endYear,
              betweenSelected: item > startYear && item < endYear,
            }"
            v-for="item in rightYearList"
            :key="item"
          >
            <a
              :class="{
                cell: true,
                _inner: true,
                selected: item === endYear || item === startYear,
              }"
              @click="onClickItem(item)"

            >
              {{ item }}
            </a>
          </div>
        </div>
      </div>
    </div>
  </div>
</template>

<script>
import moment from "moment";
const SELECT_STATE = {
  unselect: 0,
  selecting: 1,
  selected: 2,
};
export default {
  name: "yearPicker",
  computed: {
    oneSelected() {
      return (
        this.curState === SELECT_STATE.selecting &&
        (this.startYear === this.endYear || this.endYear == null)
      );
    },
    startDate() {
      return this.startYear;
    },
    leftYearList() {
      return this.yearList.slice(0, 10);
    },
    rightYearList() {
      return this.yearList.slice(10, 20);
    },
    startYearFormat() {
      if (this._.isNil(this.startYear)) {
        return null;
      }
      return moment(this.startYear).startOf("year").format("yyyy");
    },
    endYearFormat() {
      if (this._.isNil(this.endYear)) {
        return null;
      }
      return moment(this.endYear).endOf("year").format("yyyy");
    },
  },
  props: {
    width: {
      default: 200,
    },
    labelWidth: {
      default: 20,
    },
    labelText: {
      default: "",
    },
    sp: {
      default: "至",
    },
    initYear: {
      default: null,
    },
  },
  data() {
    return {
      itemBg: {},
      startShowYear: null,
      endShowYear: null,
      yearList: [],
      showPanel: false,
      startYear: null,
      endYear: null,
      curYear: 0,
      curSelectedYear: 0,
      curState: SELECT_STATE.unselect,
      showDel:false,
    };
  },
  watch:{
    startShowYear(val,oldVal){
       console.log(val)
       console.log(oldVal)
      if(val){
        this.showDel = true
      }else{
        this.showDel = false
      }
    },
  },
  methods: {
    delTime(){
      this.startShowYear = null;
      this.endShowYear = null;
      this.endYear = null;
      this.startYear = null;
      this.$emit("updateTimeRange", []);
    },
    checkStartInput(event) {
      if (isNaN(this.startShowYear)) {
        this.startShowYear = this.startYear;
      } else {
        this.startYear = this.startShowYear * 1;
        this.changeYear();
      }
    },

    checkEndInput() {
      if (isNaN(this.endShowYear)) {
        this.endShowYear = this.endYear;
      } else {
        this.endYear = this.endShowYear * 1;
        this.changeYear();
      }
    },
    changeYear() {
      if (this.startYear > this.endYear) {
        let tmp = this.endYear;
        this.endYear = this.startYear;
        this.startYear = tmp;
        this.startShowYear = this.startYear;
        this.endShowYear = this.endYear;
      }
      if (this.startYear && this.endYear) {
        this.$emit("updateTimeRange", [this.startShowYear,this.endShowYear]);
      } else {
        console.warn("WARN:年份不合法", this.startYear, this.endYear);
      }
    },
    onHoverItem(iYear) {
      if (this.curState === SELECT_STATE.selecting) {
        let tmpStart = this.curSelectedYear;
        this.endYear = Math.max(tmpStart, iYear);
        this.startYear = Math.min(tmpStart, iYear);
      }
    },
    onClickItem(iYear) {
      if (
        this.curState === SELECT_STATE.unselect ||
        this.curState === SELECT_STATE.selected
      ) {
        this.startYear = iYear;
        this.curSelectedYear = iYear;
        this.endYear = null;
        this.curState = SELECT_STATE.selecting;
      } else if (this.curState === SELECT_STATE.selecting) {
        let tmpStart = this.startYear;
        this.endYear = Math.max(tmpStart, iYear);
        this.startYear = Math.min(tmpStart, iYear);
        this.endShowYear = this.endYear;
        this.startShowYear = this.startYear;
        this.curState = SELECT_STATE.selected;
        this.$emit("updateTimeRange", [this.startShowYear,this.endShowYear]);

        setTimeout(() => {
          //为动画留的时间，可优化
          this.showPanel = false;
        }, 300);
      }
    },
    onFocus() {
      this.$nextTick(() => {
        this.showPanel = true;
      });
    },
    onBlur() {
      //   this.showPanel = false;
    },
    updateYearList() {
      let iStart = Math.floor(this.curYear / 10) * 10 - 10;
      iStart = iStart < 0 ? 0 : iStart;
      this.yearList = [];
      for (let index = 0; index < 20; index++) {
        this.yearList.push(iStart + index);
      }
    },
    closePanel(e) {
      if (!this.showPanel) {
        return;
      }
      if (typeof e.target.className !== "string") {
        this.$nextTick(() => {
          this.showPanel = false;
        });
        return;
      }
      if (
        e.target.className.indexOf("_inner") === -1 ||
        (e.target.name === "yearInput" &&
          e.target !== this.$refs.inputLeft &&
          e.target !== this.$refs.inputRight)
      ) {
        this.$nextTick(() => {
          this.showPanel = false;
        });
      }

      e.stopPropagation();
      return false;
    },
    onClickLeft() {
      this.curYear = this.curYear * 1 - 10;
      this.updateYearList();
    },
    onClickRight() {
      this.curYear = this.curYear * 1 + 10;
      this.updateYearList();
    },

    //------------------对外接口------------------------
    //直接传时间戳
    setYear(startYearStamp, endYearStamp) {
      if (!isNaN(startYearStamp) && !isNaN(endYearStamp)) {
        let startYear = moment(startYearStamp).format("yyyy");
        let endYear = moment(endYearStamp).format("yyyy");
        this.startYear = startYear * 1;
        this.endYear = endYear * 1;
        this.endShowYear = endYear * 1;
        this.startShowYear = startYear * 1;
      }
    },
  },

  created() {
    this.curYear = moment().format("yyyy");
    this.updateYearList();
  },
  beforeUnmount() {
    document.removeEventListener("click", this.closePanel.bind(this));
  },

  mounted() {
    this.$refs.yearPicker.style = "padding-left:" + this.labelWidth + "px";
    document.addEventListener("click", this.closePanel.bind(this));
  },
};
</script>
<style lang="scss" scoped>
.yearPicker {
  font-size: 14px;
  display: flex;
  position: relative;
  transition: all 0.3s;
  input:first-child {
    text-align: right;
  }
  .labelText {
    position: absolute;
    left: 8px;
  }
  background-color: #fff;
  span {
    padding: 0 8px;
    height: 26px;
    line-height: 26px;
  }
  border: 1px solid #DCDFE6;
  height: 28px;
  line-height: 28px;
  border-radius: 4px;
  padding: 0 28px 0 8px;
  box-sizing: border-box;
  .floatPanel {
    > div {
      width: 50%;
    }
    padding: 0 16px;
    position: absolute;
    display: flex;
    background-color: #fff;
    z-index: 2000;
    border-radius: 4px;
    width: 650px;
    height: 250px;
    top: 40px;
    left: -50px;
    box-shadow: 0 2px 12px 0 rgba(0, 0, 0, 0.1);
    .panelContent {
      display: flex;
      flex-wrap: wrap;
      width: 100%;
      height: calc(100% - 70px);
      .oneSelected {
        border-top-right-radius: 24px;
        border-bottom-right-radius: 24px;
      }
      .startSelected {
        background-color: #F2F6FC;
        border-top-left-radius: 24px;
        border-bottom-left-radius: 24px;
      }
      .endSelected {
        background-color: #F2F6FC;
        border-top-right-radius: 24px;
        border-bottom-right-radius: 24px;
      }
      .betweenSelected {
        background-color: #F2F6FC;
      }
      > div {
        width: 75px;
        height: 48px;
        line-height: 48px;
        margin: 3px 0;
        // border-radius: 24px;
        text-align: center;
        a {
          display: inline-block;
          width: 60px;
          height: 36px;
          cursor: pointer;
          line-height: 36px;
          border-radius: 18px;
        }
        .selected {
          background-color: #409EFF;
          color: #fff;
        }
      }
    }
    .panelHead {
      position: relative;
      height: 46px;
      line-height: 46px;
      text-align: center;
      i {
        position: absolute;
        cursor: pointer;
        &:hover {
          color: #409EFF;
        }
      }
    }
    .rightPanel {
      padding-left: 8px;
    }
    .leftPanel .panelHead i {
      left: 20px;
    }
    .rightPanel .panelHead i {
      right: 20px;
    }
  }
  .floatPanel::before {
    content: "";
    height: 100%;
    position: absolute;
    left: 50%;
    width: 1px;
    border-left: 1px solid #e4e4e4;
  }
}
input {
  width: 60px;
  border: none;
  height: 26px;
  line-height: 26px;
  box-sizing: border-box;
  background-color: transparent;
  text-align: center;
}
input:focus {
  outline: none;
  background-color: transparent;
}
input::-webkit-input-placeholder { /* WebKit, Blink, Edge */
  color : rgba(144, 147, 153, 0.8);
  font-size:12px;
}
.yearPicker:hover {
  border-color: #409EFF;
}
.dateIcon {
  position: absolute;
  top: 6px;
  left:5px;
  color: #adb2bc;
}
.delIcon{
  position: absolute;
  top: 6px;
  right:6px;
  color: #adb2bc;
}
</style>
